A conventional fixing device includes a cylindrical fusing film, a heater provided in an internal space of the fusing film, a pressure roller disposed opposite to the heater with respect to the fusing film, and a circular flange member for restricting a displacement of the fusing film in an axial direction thereof. A sheet carrying a toner image is passed through a nip portion defined between the circular film and the pressure roller, so that the toner image can be thermally fixed onto the sheet.
The circular flange member has a regulation portion to which an axial end portion of the fusing film is abutted for regulating axial displacement of the film. The circular flange member also has a guide portion integral with the regulation portion and in sliding contact with an inner peripheral surface of the film for guiding rotation of the film. The regulation portion extends in a direction perpendicular to a rotation axis of the cylindrical film. Such conventional fixing device is disclosed in Japanese Patent Application Publication No. 2009-237089.